The state agency took over the investigation from the Jackson Police Department.

The men died in a third-floor room Thursday where Smith was interrogating Powell after his arrest. Powell had been arrested in connection with the stabbing death earlier this week of a 20-year-old Jackson man.

Autopsies were to be performed Friday, said Hinds County Coroner Sharon Grisham-Stewart.

City and state officials continued to mourn the death of Smith, a detective who had led the investigation of a number of high-profile murder cases in Mississippi's largest city. Smith, 40, was described as a tall and fit officer who had been with the department since 1995.

"Let us all come together as a city to mourn the loss of this exceptional member of the Jackson Police Department family," Johnson said in a statement. "Though we will never know the full measure of sorrow experienced by the family of Detective Smith, we can let them know that we stand with them during this difficult time."

Gov. Phil Bryant, a former Hinds County sheriff's deputy, also noted Smith's passing at a ceremony marking the 75th anniversary of the Mississippi Highway Patrol.